Suspended trolley conveyor system

ABSTRACT

This disclosure relates to a trolley construction, preferably for a power-and-free conveyor system, wherein a central casting is supported on either side by a plurality of wheels. Each wheel has an outer race and an inner race separated by bearings. The inner race of each wheel is removably fixed to a shaft which extends from a central casting so that the wheels can be removed and replaced or repaired. Key locks on the inner race engage milled slots on the central casting and/or the supporting shaft to prevent relative rotation between the central casting, the supporting shaft and the inner race.

United States Patent 721 Ruben E. Fm;

Fredrkk R. Sytsma, both of Grand Rapids, Mich.

May 1, 1969 Aug. 31, 1971 v C. L. Frost 8: Son, Inc.

Grand R P Mich.

Inventors Appl. No. Filed Patented Assignee [54] SUSPENDED TROLLEY CONVEYOR SYSTEM 16 Claims, 4 Drawing Figs.

References Cited UNITED STATES PATENTS Primary Examiner-Arthur L. La Point AssllrtanfExaminer-Howmd Beltran Attorney-Price, l-leneveld, Huizenga & Cooper ABSTRACT: This disclosure relates to a trolley construction, preferably for a power-and-free conveyor system, wherein a central casting is supported on either side by a plurality of wheels. Each wheel has an outer race and an inner race separated by bearings. The inner race of each wheel is removably fixed to a shaft which extends from a central casting so that the wheels can be removed and replaced or repaired. Key locks on the inner race engage milled slots on 553,621 l/l896 Kraus 308/187 the central casting and/or the supporting shaft to prevent rela- 556,249 3/1896 Brandenburg. 308/192 tive rotation between the central casting, the supporting shaft 605,208 6/1898 Skarin 301/6 D and the inner race.

I 6 T .22 z 22 K 20 PATENTED AUBB'I lQYI 3.602.150

sum 2 [1F 2 FIG. 4

FIG. 3

INVENTORS RUBEN E. FROST FREDERICK R. sYT MA BY 6 M, iw

ATTORNEYS SUSPENDED TRULLEY CONVEYOR SYSTEM This invention relates to a trolley assembly. In one of its aspects, it relates to a trolley assembly wherein roller bearing wheels have inner race members keyed to a central casting and wherein the wheels are removably secured to a supporting shaft.

in another of its aspects, the invention relates to a trolley assembly wherein roller bearing wheels support a central casting and the inner race of the wheels is keyed to a shaft on which it is supported.

In another of its aspects, the invention relates to a trolley assembly wherein a central casting is supported on either side by a plurality of roller bearing wheels, wherein the roller bearing wheels are removably secured to supporting shafts which extend out from the central casting.

Power-and-free conveyor systems are overhead conveyors having a trolley with a central casting for supporting work arti- .11,

cles. The trolleys are driven by a power actuated element or the trolleys are released for free running or storage. The central casting is supported on roller bearing wheels through shafts which extend out of the casting. Conventionally the wheels are put onto the shafts by swedging the end of the shaft after the wheels have been put on the shaft so that the wheel is retained on the shaft by the expanded end. When the bearing wears out, the inner race of the wheels occasionally becomes disengaged from the shaft and rotates on the shaft, thereby machining the shaft. At this point, the entire shaft and the wheels need to be replaced. If the defective wheel continues to rotate on the shaft, the result is that the shaft breaks and the casting separates from the wheel. As the casting is quite heavy, a dangerous condition results.

In order to replace the wheels or to service the wheels, the entire shaft and wheel assembly must be removed. Frequently, the whole trolley assembly is replaced. Occasionally, while attempting to remove the wheel from the shaft, the inner race of the wheel is damaged and must therefore be replaced.

U.S. Pat. No. 3,033,128 to Czarneclti discloses a trolley construction of this nature wherein the wheel assemblies are made removable by using a split shaft which is held together through a pin extending up through a central portion of the central casting. The assembly is complicated and requires redesign of the central casting.

We have now discovered an improved trolley assembly. especially applicable to the power-and-free conveyor system, wherein the inner races of the roller bearing wheels are removably secured to their supporting shafts in a simple and efiicient manner, and wherein the inner races are keyed to the supporting shafts and/or the central casting to prevent wear between these parts.

By various aspects of this invention one or more of the fol-- lowing, or other, objects can be obtained.

it is an object of this invention to provide an improved trolley assembly for a power-and-free conveyor system wherein the wheels are easily repaired and replaced without damage to parts.

It is a further object of this invention to provide an improved trolley assembly having removable wheels which assembly is easily adaptable to older conveyor systems with a minimum of cost and effort.

It is yet another object of this invention to provide an improved trolley assembly wherein the wheels are easily serviced.

It is a further object object of this invention to provide an improved trolley assembly wherein the wear on supporting shafts by the inner race is avoided.

It is a-further object of this invention to provide an im proved conveyor system having a central body supported on roller bearing wheels through shafts which extend out from the central body wherein wear between the central body and the supporting shafts is avoided.

mix. h. r

All

It is a further object of this invention to provide an improved conveyor system having a central body supported on roller bearing wheels through shafts which extend out from the central body wherein wear between the central body and the inner race is avoided.

it is yet another object of this invention to provide an improved conveyor systern having a central body supported on roller bearing wheels through shafts: which extend out from the central body wherein wear between the inner race of the wheels and the supporting shafts is avoided.

Other aspects, objects, and the several advantages of this invention are apparent to one skilled in the art from a study of this disclosure, the drawings, and the appended claims.

According to this invention, there is provided a trolley assembly wherein a central body is supported on opposing sides by first and second wheel members, a shaft extends through the central body and joins the first and second wheel members, supporting the central body thereon. Each of the wheel members includes an inner race and an outer race separated by bearing members. Means are provided on the shaft to removably secure each inner race member to the shaft. lnterloclring means are fixed between the inner race member and the shaft member to prevent relative rotation between the shaft and the inner race member.

Further according to the invention, means are provided between each of the inner race members and the central body to prevent relative rotation between the inner race members and the central body.

In another embodiment, the invention relates to a powerand-free conveyor system comprising a central supporting member, a shaft means extending out of either side of the central supporting member, and wheel means on the shaft means adapted to roll on inwardly directed tracks. Each of the wheel means comprises an outer race member, an inner race member, and bearing means between the outer and inner race members, means for sealing lubricant between the outer and inner race members. Means are provided for removably fixing each of the inner race members to the shaft means so that each of the wheels can be removed and replaced or disassembled without destroying the structure of the shaft means or the wheel members.

The invention will now be described with reference to the accompanying drawings in which:

FIG. l is a side elevational view, partly in section, of a power-and-free conveyor system employing a first embodimerit of the invention;

E is an elevational view, in section, taken along lines i' 'lrll. l; MG. 3 is a sectional view seen along lines 3-3 of FIG. 2; and

ilG. 4 is a sectional view similar to FIG. 1 showing a second embodiment of the invention.

iieferring now to the drawings, and to EMS. 1-3 in particular, there is shown a power-and-free trolley assembly in which a central casting 12 is supported by wheels 14 on one side and wheels lid on the other side. The wheels ride on rail forming channels ill and 20 which are directed inwardly. The trolley can be driven by a cog l3 which is attached to a separate conveyor chain (not shown l. Alternately the cog 13 can be disengaged from the casting l2 so that the casting can be pushed along the rails iii and M) by hand, or remain in a storage bank.

Each wheel of the trolley assembly has an outer race 22 and an inner race 224 which are separated by ball bearings 26. An

inner seal structure 23 seals lubricant into the bearing area and a Welsh plug 30 seals the lubrication on the outer side of the wheels. A grease fitting 32 is provided on the Welsh plug Elli for t-e introduction of lubricants into the bearing area of each wheel. Each inner race 24 has a projecting lug 34 extending axially inwardly and radially inwardly.

Each inner race 24 is fixed onto a stud shaft 36 through threaded end plugs 44 which threadably engage the ends of the shaft. Each inner race 24 has an annular bevel 42 against which bears an expanded head of the threaded end plug 44.

An Allen wrench hole 46 is provided in the end of the end plug 44 to facilitate fixing and removing of the threaded end plug to the stud shaft 36.

A slot 38 is milled longitudinally along a side of the stud shaft 36 and engages the projecting lugs 34 of the inner races 24.

The casting 12 has a circular bore 48 in which the stud shaft 36 is positioned. Slots 50 and 52 are milled at the upper ends of the annular bore 48 for engaging the projecting lugs 34 of the inner race members.

The trolley assembly is easily constructed by inserting the shaft 36 into the casting bore 48, putting the wheels on the shaft such that the projecting lugs 34 engage the milled slots 50 and 52 in the casting, and engage the milled slot 38 in the stud shaft 36. The threaded end plugs 44 are then screwed into the ends of the stud shaft 36 to hold the wheels onto the stud shaft 36. The Welsh plugs 30 are then inserted into the outer ends of the wheel to seal off the bearing area. By this construction the inner race of the wheel is keyed to central casting 12 as well as to the stud shaft 36.

In the event that the wheels need to be repaired or replaced, the Welsh plug is removed and the end plug 44 is unscrewed. The wheels can be removed from the stud shaft 36 by inserting an allen wrench into the hole 46 and unscrewing the end plug 44. The wheel is then simply pulled from the stud shaft and a new wheel replaced. This ease of wheel replacement is of substantial advantage in reducing replacement costs and reducing maintenance costs. The replacement of wheels and axles takes place while the trolley is in place in the conveyor system without the need to shut down the conveyor for substantial lengths of time or without the need to destroy the casting or remove the same from the system.

The keying of the inner race to the stud shaft 36 maintains the inner race 24 fixed relative to the stud shaft 36 so that there is no wear between the stud shaft and the inner race. .Further, the keying of the inner race to the casting 12 through the slots 50 and 52 prevent relative rotation and relative movement between the casting l2 and the inner race 24. Further, the projecting lugs 34 prevent relative rotation between the casting l2 and the stud shaft 36 thereby eliminating wear on the stud shaft 36 due to relative movement between the bore 48 of the casting l2 and the stud shaft 36.

Since most trolley assemblies have a bore 48 for receiving a stud shaft on which the wheels are fixed, the existing trolley assemblies can be modified .to use the invention by simply milling slots 50 and 52 in the casting 12. Thus, the conveyor system is easily adaptable to existing systems.

Reference is now made to FIG. 4 in which there is shown a modified form of the invention. Wheels 62 and 64 are removable fixed to a stud shaft 98 which supports a central casting 12. The wheel 62 has an inner race 66 and an outer race 68 which are separated by ball bearings 70. An outer seal 72 and an inner seal 74 close off the bearing area to retain lubrication therein. A tapped hole 76 is provided in the race 72 for receiving a threaded end 100 of the stud shaft 98. The inner race 66 also has a lubricating passage 82 which communicates at one end with the bearing area and at the other end with an annular counterbore 80. A projecting lug 78 extends inwardly from the inner race 66.

The wheel 64 has an inner race 83 and an outer race 84 separated by ball bearings86. An inner seal 88 and an outer seal 90 close off the bearing area to retain lubrication therein. A projecting lug 92 is formed on an innner edge of the inner race 83. A lubricating passage 94 communicates at one end with the bearing area and at the other end with an annular counterbore 95. A circulatr bore 96 is formed in the outer end of the inner race 83 for receiving the head 102 of the stud shaft 98. An allen wrench hole 104 to facilitate the attaching and detaching of the stud shaft 98 to the wheels. Lubricating passages 108 and 106 are bored, respectively, in either end of the stud shaft 98 to permit lubricant to pass into the bearing area from the outside of the wheels. For this purpose, lubricating nipples are placed in the end of each lubricating passage.

The casting 12 has milled slots 50 and 52 as in the first embodiment to engage the projecting lugs 78 and 92 from the inner races 66 and 83 respectively. v

In this embodiment, the central casting 12 is keyed to the inner race of each respective wheel. Thus, relative movement between the inner races and the central casting 12 is eliminated.

In this modification, the ease of removing and replacing wheels is apparent. If the wheels are to be removed, the shaft 98 is merely rotated with the aid of an allen wrench inserted into hole 104. When the stud shaft 98 has been unscrewed from its connection with inner race 66, the stud shaft 98 is removed by withdrawing it to the left as viewed in FIG. 4. The wheels 62and 64 are then easily removed and serviced or replaced. During the removal operation, the inner race 66 will not rotate since it is keyed through projecting lugs 78 to the central casting 12.

The wheels and axles can be replaced and repaired while the trolley is in the system and with'the same ease as the embodiment illustrated in FIGS. 1-3.

As an alternate embodiment (not shown) separate and independent keys can be employed in lieu of the integrally formed projecting lugs on the inner races. In this modification, slots would be milled in the inner side of the inner races as well as in the stud shafts and the central casting. The key would therefore lock the central casting to the shaft and to the wheel inner races.

In the embodiments shown, lubrication is easily supplied to the bearing area through the lubrication passages indicated.

Whereas the invention in FIG. 4 has been described with a threaded engagement between the stud shaft 98 and the inner race 66, it is within the scope of this invention to provide a counterbore within the inner race 66 and to provide a threaded plug to secure the inner race to the stud shaft, the threaded plug threadably engaging the stud shaft.

Reasonable variation and modification are possible within the scope of the foregoing disclosure, the drawings, and the appended claims without departing from the spirit of the invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a trolley assembly wherein a central body is supported on opposing sides by first and second wheel members, a shaft means extends out from said central body and is fixed to said wheel members so that said central body is supported on said wheel members, each of said first and second wheel members including an inner race and an outer race separated by bearing members, the improvement which comprises:

portions of said shaft means extending beyond each side of said central body and contained substantially within the confines of said races;

means associated with said shaft portions and accessible from the side of at least one of said wheels for removably securing said shaft means to each inner race member without removing said trolley from the track on which it is located and without destroying subsequent use of said shaft means in combination with a new wheel or wheels; and

interlocking means between said inner race members and said shaft member to prevent rotation between said shaft and said inner race member.

2. A trolley assembly according to claim 1 further comprising means interlocking said central body and said inner race.

3. A trolley assembly according to claim 1 further comprising means interlocking said central body with said shaft means.

4. A trolley assembly according to claim 1 wherein said removably securing means comprises at least one threaded end plug which threadably engages an end of said shaft means and bears against an outer portion of said inner race.

5. A trolley assembly according to claim 1 wherein said removably securing means comprises a pair of end plugs, each inner race being fixed to said shaft means through an end plug,

each end plug having a head member abutting against an outer portion of said inner race, and a stud portion extending through said inner race from said head member, said stud portion threadably engaging an end portion of said shaft means.

6. A trolley assembly according to claim wherein said interlocking means comprises a milled slot in said shaft means and a key member on said inner race projecting into said milled slots.

7. A trolley assembly according to claim 6 further comprising a milled slot in said central body adjacent said inner race, said key member projecting into said central body milled slot whereby said central body is keyed to said inner race.

8. A trolley assembly according to claim 1 wherein said interlocking means comprises a milled slot in said shaft member and a key member on said inner race projecting into said milled slot.

' 9. A trolley assembly according to claim 1 further comprising lubricating passages between the outside portion of said first and second wheel members and said bearings, and means sealing said bearings to maintain lubrication within said outer and inner races.

10. The trolley assembly of claim l in which one of the portions of the shaft means which extends from one side of said central body includes a head in abutting engagement with the inner race of one of the wheel members and the other portion of the shaft means which extends from the other side of said central body includes a threaded portion threaded into a threaded opening in the inner race of the other wheel member.

11. The trolley assembly of claim 1 in which a removable cap 5 secured to the outer side of each of said outer races to contain lubricant between the inner and outer races within the confines thereof.

12. In a trolley assembly wherein a central body is supported on opposing sides by first and second wheel members, a shaft means having portions extending out of both sides of said central body, and said first and second wheel members are fixed onto said shaft means so that said central body is supported by said wheel members through said shaft, each of said first and second wheel members including an inner race and an outer race separated by bearing members, the improvement which comprises:

said portions of said shaft means each having an axial threaded opening in the end thereof and a threaded end plug removably secured therein whereby said shaft means is removably secured to each of said inner race members.

13. A trolley assembly according to claim 1 further comprising a milled slot in said central body adjacent said inner race, and a key member on said inner race projecting into said central body milled slot wherein said central body is keyed to said inner race.

14. The trolley assembly of claim 12 in which is provided interlocking means between each of said inner race members and said central body to prevent relative rotation between said inner race members and said central body.

115. A power-and-free conveyor system comprising:

a central supporting member;

a shaft means extending out of either side of said central supporting member;

wheel means adapted to roll on inwardly directed tracks,

each of said wheel means comprising an outer race member, an inner race member and bearing means between said outer and inner race members;

means removably fixing each of said. inner race members to said shaft meanssuch that each of said wheels can be removed and replaced or disassembled without destroying the structure of said shaft or said wheel members;

said means including a head on one end of said shaft in abutting engagement with the inner race of one of said wheel members, and a threaded portion on the other end of said shaft, the inner race of the other of said wheel members having a tapped hole to 'threadably engage said threaded portion of said shaft.

16. A power-and-free conveyor system according to claim 15 further comprising a lubricating passage from the outside of each wheel to said bearing area between said inner race member and said outer race member. 

1. In a trolley assembly wherein a central body is supported on opposing sides by first and second wheel members, a shaft means extends out from said central body and is fixed to said wheel members so that said central body is supported on said wheel members, each of said first and second wheel members including an inner race and an outer race separated by bearing members, the improvement which comprises: portions of said shaft means extending beyond each side of said central body and contained substantially within the confines of said races; means associated with said shaft portions and accessible from the side of at least one of said wheels for removably securing said shaft means to each inner race member without removing said trolley from the track on which it is located and without destroying subsequent use of said shaft means in combination with a new wheel or wheels; and interlocking means between said inner race members and said shaft member to prevent rotation between said shaft and said inner race member.
 2. A trolley assembly according to claim 1 further comprising means interlocking said central body and said inner race.
 3. A trolley assembly according to claim 1 further comprising means interlocking said central body with said shaft means.
 4. A trolley assembly according to claim 1 wherein said removably securing means comprises at least one threaded end plug which threadably engages an end of said shaft means and bears against an outer portion of said inner race.
 5. A trolley assembly according to claim 1 wherein said removably securing means comprises a pair of end plugs, each inner race being fixed to said shaft means through an end plug, each end plug having a head member abutting against an outer portion of said inner race, and a stud portion extending through said inner race from said head member, said stud portion threadably engaging an end portion of said shaft means.
 6. A trolley assembly according to claim 5 wherein said interlocking means comprises a milled slot in said shaft means and a key member on said inner race projecting into said milled slots.
 7. A trolley assembly according to claim 6 further comprising a milled slot in said central body adjacent said inner race, said key member projecting into said central body milled slot whereby said central body is keyed to said inner race.
 8. A trolley assembly according to claim 1 wherein said interlocking means comprises a milled slot in said shaft member and a key member on said inner race projecting into said milled slot.
 9. A trolley assembly according to claim 1 further comprising lubricating passages between the outside portion of said first and second wheel members and said bearings, and means sealing said bearings to maintain lubrication within said outer and inner races.
 10. The trolley assembly of claim 1 in which one of the portions of the shaft means which extends from one side of said central body includes a head in abutting engagement with the inner race of one of the wheel members and the other portion of the shaft means which extends from the other side of said central body includes a threaded portion threaded into a threaded opening in the inner race of the other wheel member.
 11. The trolley assembly of claim 1 in which a removable cap s secured to the outer side of each of said outer races to contain lubricant between the inner and outer races within the confines thereof.
 12. In a trolley assembly wherein a central body is supported on opposing sides by first and second wheel members, a shaft means having portions extending out of both sides of said central body, and said first and second wheel members are fixed onto said shaft means so that said central body is supported by said wheel members through said shaft, each of said first and second wheel members including an inner race and an outer race separated by bearing members, the iMprovement which comprises: said portions of said shaft means each having an axial threaded opening in the end thereof and a threaded end plug removably secured therein whereby said shaft means is removably secured to each of said inner race members.
 13. A trolley assembly according to claim 1 further comprising a milled slot in said central body adjacent said inner race, and a key member on said inner race projecting into said central body milled slot wherein said central body is keyed to said inner race.
 14. The trolley assembly of claim 12 in which is provided interlocking means between each of said inner race members and said central body to prevent relative rotation between said inner race members and said central body.
 15. A power-and-free conveyor system comprising: a central supporting member; a shaft means extending out of either side of said central supporting member; wheel means adapted to roll on inwardly directed tracks, each of said wheel means comprising an outer race member, an inner race member and bearing means between said outer and inner race members; means removably fixing each of said inner race members to said shaft means such that each of said wheels can be removed and replaced or disassembled without destroying the structure of said shaft or said wheel members; said means including a head on one end of said shaft in abutting engagement with the inner race of one of said wheel members, and a threaded portion on the other end of said shaft, the inner race of the other of said wheel members having a tapped hole to threadably engage said threaded portion of said shaft.
 16. A power-and-free conveyor system according to claim 15 further comprising a lubricating passage from the outside of each wheel to said bearing area between said inner race member and said outer race member. 